• Title/Summary/Keyword: Frequency-of-Occurrence

Search Result 1,427, Processing Time 0.032 seconds

A Study on Daily Temperature Cycle of Environmental Test in the Korean Peninsula (한반도 지역의 환경시험 온도 일주기 연구)

  • Lee, Jeong-Yong
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.10 no.3
    • /
    • pp.62-70
    • /
    • 2007
  • Most design temperature of environmental test in korea is based on the standard of Department of Defense. There are few studies to establish temperature standard. Besides the representative environmental test guide 'MIL-STD-810F' encourage to tailor to generate the most relevant test data possible and to test to make a match of test environment with operational environment. Under these circumstances, it is irrational to comply with baseless daily cycle. Thus the study about design method of test temperature is essential. So, the daily cycles to be appropriate to the Korean peninsula was presented in this study. And this research shows how to derive two main element, frequency-of-occurrence and daily maximum (minimum) temperature in daily cycles, in case we can not find the daily cycle.

A Study on the Time-Frequency Analysis of Transient Signal using Wavelet Transformation (Wavelet 변환을 이용한 과도신호의 시간-주파수 해석에 관한 연구)

  • 이기영;박두환;정종원;김기현;이준탁
    • Proceedings of the Korean Society of Marine Engineers Conference
    • /
    • 2002.05a
    • /
    • pp.219-223
    • /
    • 2002
  • Voltage and current signals during impulse tests on transformer are treated as non-stationary signals. A new method incorporating signal-processing method such as Wavelets and courier transform is proposed for failure identification. It is now possible to distinguish failure during impulse tests. The method is experimentally validated on a transformer winding. The wavelet transforms enables the detection of the time of occurrence of switching or failure events. After establishing the time of occurrence, the original waveform is split into two or more sections. The wavelet transform has ability to analysis the failure signal on time domain as well as frequency domain. Therefore, the wavelet transform is superior than courier transform to analysis the failure signal. In this paper, the fact was proved by real data which was achieved.

  • PDF

Pilot Study on the Statistical Characteristics of a Railroad Weather-Related Accidents and Incidents in Korea (철도기상사고의 통계적 특성)

  • Park, Jong-Kil;Jung, Woo-Sik;Lee, Man-Ki;Kim, Hi-Man;Lee, Jae-Su
    • Proceedings of the KSR Conference
    • /
    • 2010.06a
    • /
    • pp.1725-1731
    • /
    • 2010
  • This paper aims to find out the statistical characteristics of the railroad accidents by weather phenomena. For this, It is investigated occurrence frequency of railroad accidents and operation obstacles from 1996 to 2008 in Korea using the KROIS data and Korea railroad accidents reports. The results are as follows; The occurrence frequency of railroad accidents and operation obstacles decrease gradually, and most of railroad accidents is a railroad traffic accidents. The amount of damages by a railroad weather-related accidents is higher than the one of the railroad accidents and operation obstacles. Weather events which is influenced the railroad weather-related accidents and incidents are rainfall, snowfall, lightning, strong winds. And they have occurred a railroad weather-related accidents and incidents, such as rail obstruction, signal failure, and power supply failure.

  • PDF

Damage detection of shear buildings using frequency-change-ratio and model updating algorithm

  • Liang, Yabin;Feng, Qian;Li, Heng;Jiang, Jian
    • Smart Structures and Systems
    • /
    • v.23 no.2
    • /
    • pp.107-122
    • /
    • 2019
  • As one of the most important parameters in structural health monitoring, structural frequency has many advantages, such as convenient to be measured, high precision, and insensitive to noise. In addition, frequency-change-ratio based method had been validated to have the ability to identify the damage occurrence and location. However, building a precise enough finite elemental model (FEM) for the test structure is still a huge challenge for this frequency-change-ratio based damage detection technique. In order to overcome this disadvantage and extend the application for frequencies in structural health monitoring area, a novel method was developed in this paper by combining the cross-model cross-mode (CMCM) model updating algorithm with the frequency-change-ratio based method. At first, assuming the physical parameters, including the element mass and stiffness, of the test structure had been known with a certain value, then an initial to-be-updated model with these assumed parameters was constructed according to the typical mass and stiffness distribution characteristic of shear buildings. After that, this to-be-updated model was updated using CMCM algorithm by combining with the measured frequencies of the actual structure when no damage was introduced. Thus, this updated model was regarded as a representation of the FEM model of actual structure, because their modal information were almost the same. Finally, based on this updated model, the frequency-change-ratio based method can be further proceed to realize the damage detection and localization. In order to verify the effectiveness of the developed method, a four-level shear building was numerically simulated and two actual shear structures, including a three-level shear model and an eight-story frame, were experimentally test in laboratory, and all the test results demonstrate that the developed method can identify the structural damage occurrence and location effectively, even only very limited modal frequencies of the test structure were provided.

A Study on Incidence of Bacteriuria according to Bladder Irrigation in Patients with Indwelling Catheter (유치도요관 환자의 방광 세척에 따른 요로 감염 발생 빈도에 관한 연구)

  • 고경옥
    • Journal of Korean Academy of Nursing
    • /
    • v.20 no.1
    • /
    • pp.38-49
    • /
    • 1990
  • The Purpose of this study is for clinical nurses to be aware of the significance of prevention against bacteriuria caused form foley catheterization, through probing variables related to the occurrence of bacteriuria which appears as the most frequent occurring infection, and try to lower bacteriuria by applying to nursing care at the clinical. For this study 46 patients with catheterization and the closed drainage system were sampled and investigated from among patients at Intensive Care Unit in Two hospitals affiliated to K University in Seoul. Those patients sampled had not shown bacteriuria before foley catheterization. The research design is to explore the effectiveness of prevention against bacteriuria in accordance with bladder irrigation and no bladder irrigation. Especially, the frequency of occurrence of bacteriuria examined so as to compare the effectiveness of bladder irrigation depending on the type of foley catheter between 2-lumen foley catheter and 3-lumen foley catheter. The results Were as follows. 1. The occurrence of bacteriuria in patient with bladder irrigation was 21.7%, while in patient without bladder irrigation 26.1%. 2. The occurrence of bacteriuria in patient without bladder irrigation according to duration of Indwelling catheter, was 4.3% after 48 h, 8.7% after 72 h and 21.7% after 96 h. 3. In case of 2-lumen foley catheter the occurrence of bacteriuria in patient with bladder irrigation was 0% after 72 h, and 4.35% after 96 h. In case of 3-lumen foley catheter, the occurrence of bacteriuria in patient with bladder irrigation was 13% after 48 h, 8.7% after 72 h and 4.3% after 96 h. 4. The occurrence of bacteriuria according to duration of catheterization was 8.7% after 48 h, 8.7% after 72 h and 15.2% after 96 h. In sex, female was 35% and male 15.4%. 5. The occurrence of bacteriuria according to mental state was 15% in clear state, while 29.6% in mental disorder. 6. In regard to a kind of microorganism induced bacteriuria, Gram negative bacteria was 63.7%, Gram positve bacteria 36.3%.

  • PDF

An Analysis of Suicidal Accidents on Psychiatric In-patients (입원중 정신병 환자의 자살사고 요인 분석)

  • 이평숙
    • Journal of Korean Academy of Nursing
    • /
    • v.5 no.2
    • /
    • pp.11-22
    • /
    • 1975
  • Suicides have been considered to be one of the grave problems of modern societies. According to recent police statistics of Republic of Korea, 28.6 suicides in every 100, 000 were reported. Psychiatric Patients are believed to be predisposed to suicidal tendencies. This study was performed to investigate the characteristics of suicidal attempts and to analyse the environmental factors involved in the suicidal accidents of patients admitted to psychiatric hospitals. Records of 66 suicidal accidents from three psychiatric hospitals during the period of January 1971 through June 1971 were sampled. Data were analysed by percentile score. Results are as follows; 1. The age group of 21~30yrs. was revealed to be the highest in frequency of suicidal attempts (50.0%) Among the unsuccessful suicides; the age group of 31~40yrs. in men and the age group of 21~30 yrs. in women revealed to be the highest in frequency-Among the unsuccessful suicides; the age group of 21-30 yrs. in both sex revealed to be the highest in frequency. 2. Suicidal accidents occurred more frequently to the unmarried(63.6%)- Among the successful suicides; higher frequency was shown to unmarried in men and the frequency is contrasted in women. Among the unsuccessful; the unmarried in both sex were revealed to be highest in frequency. 3. Schizophrenia was revealed the highest of suicidal attempts in frequency (81.8%). 4, Suicides were most frequently attempted in the spring(46, 9%). Among the successful suicides; highest frequencies were shown in men in tile winter and in women in the summer season. Among the unsuccessful suicides :highest frequencies were shown in men in the winter and in women in the spring. 5. Suicidal attempts were most frequently occurred in hospital wards (40.9%), In women, unsuccessful attempts were found to be the highest on authorized leave at their homes. 6. The hanging was revealed to be the most frequently adopted methods for suicidal attempts (31.8%). Among the successful suicides; hanging was the most frequent method adopted in men white in women the drug over-dose, Among the unsuccessful suicides ; stabbing by sharp devices while in women drug-overdosage was adopted as well 7. The most frequently adopted instrument of different suicidal attempts were: house-hold wrapper (26.3%) in cases of hanging, knives (31.8%) in cases of stabbing, and drugs. 8. The suicidal attempts have occurred most frequently at dawn through early morning (2-6A. M.) (34.8%). Among the successful suicides i most frequent time of occurrence on week-days were revealed to be dawn, while on holidays the occurrence were in the evening as well Among the unsuccessful; the most frequent time of occurrence was the day hours while on holidays at dawn. 9. Suicidal attempts within the hospital ward were first noticed by nurses most frequently (42.2%). 10. Manifestations such as restlessness, depression, self-depreciation were revealed to be the most frequent pre-suicidal attempt behavior characteristics. 11. Among the successful suicides ; manifestations of physical damage were found on the neck while among unsuccessful attempts, the damages were found on exterminates.

  • PDF

A RADIOGRAPHIC STUDY OF DILACERATED SINGLE ROOTED TOOTH (치근단 X선사진을 이용한 만곡치의 연구)

  • Kim Chung-Woo;Hwang Eui-Hwan;Lee Sang-Rae
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
    • /
    • v.20 no.2
    • /
    • pp.227-234
    • /
    • 1990
  • The purpose of this study was to evaluate the incidence and several radiographic features of dilacerated teeth in 2132 full month radiograms in Korean. The results were as follows: 1. The occurrence was revealed to 2.7% in total examined teeth, and these anomalies were occurred in maxilla (52.4%) more than in mandible (47.6%). 2. There was a predilection for occurrence of dilaceration in female, which included 12.8% of the female compared to 11.3% in male. 3. The frequency of dilaceration in male, which included 40.5% in maxilla and 59.5% in mandible. The frequency of dilaceration in female, which included 52.4% in maxilla and 47.6% in mandible. 4. The order of frequency of dilaceration was second premolar, first premolar, lateral incisor, canine in maxilla, and first premolar, second premolar, canine, lateral incisor, central incisor in mandible. 5. In classifying of dilacerated teeth into 3 types by following appearances such as root curvature. Distal dilaceration was by far most common containing 65.8% of the cases. The least frequent was mesial dilaceration, which included 6.5% of the cases.

  • PDF

Characteristics of the Radio-Frequency/Vacuum Drying of Heavy Timbers for Post and Beam of Korean Style Housings Part I : For Japanese larch round logs with 150 mm and 210 mm in diameter and 2,500 mm in length

  • Lee, Nam-Ho;Zhao, Xue-Feng;Shin, Ik-Hyun;Park, Moon-Jae;Park, Jung-Hwan;Park, Joo-Saeng
    • Journal of the Korean Wood Science and Technology
    • /
    • v.39 no.2
    • /
    • pp.125-131
    • /
    • 2011
  • The characteristics of radio-frequency/vacuum drying Japanese larch boxed heart round logs with 150 mm and 210 mm in diameter and 2,500 mm in length, subjected to compressive loading, after the pretreatment of kerf were investigated. The results of this study were as the follows: The drying time of about 120 hours~130 hours was needed from green to about 15 percent of moisture content. The gradient of final moisture content for all specimens was very gentle in both longitudinal and transverse directions owing to dielectric heating. The surface checks seriously occurred although the occurrence extent of surface check for the kerfed specimens was slight compared with that for the control specimens because drying stress was relieved by kerf. The occurrence of surface checks for the L-specimen was more serious than that for the S-specimen.

A Compatibility Assessment and Verification of Suitable to DICOM of PACS DATA CD : Current Situation Investigation of Korea (PACS DATA CD의 호환성 평가 및 DICOM 적합성에 대한 검증을 통한 기준 제시)

  • Jeong, Jae-Ho;Sung, Dong-Wook;Park, Bum-Jin;Son, Gi-Gyeong;Kang, Hui-Doo
    • Korean Journal of Digital Imaging in Medicine
    • /
    • v.10 no.1
    • /
    • pp.29-34
    • /
    • 2008
  • Purpose To analyze the input and output error of data CD which records the image information and the problems of the server of the compatibility. And to report a compatibility assessment and verification of suitable to DICOM of PACS data CD with investigation of current situation of Korea METHOD AND MATERIALS Date CD of each 8 vendors in 30 hospitals was analyzed. We grasped a main verification element existence of a generation compatibility of data CD. The items of element are media identification, DICOM compression, DICOM viewer send, specified object information modify, auto-run, DICOM content type, etc, and give 1 point for each item. We divided the assessment about an each item into 5 levels. Verification about. DICOM conformance by using DICOM validation tool kit is shown to be classified pass or fail according to error occurrence of tag valus. Classify the prequency of tag occurrence as the item. RESULTS The average point of date CD compatibility is 8 point (very good), lowest is 5 point (6.6%), and highest is 10 point (23%_. Most high occurrence frequency's distribution is 7 point (36.6%). As a result of verification about DICOM conformance, PASS in 8 occurrence frequency's distribution is 7 point (36.6%). As a result of verification about DICOM maximum length numbers (14 items), DICOM error of modality (10 items), discord of pixel data length (6 items). etc.

  • PDF